Various telephone private branch exchanges are known that, in addition to having the capability for the actual exchange control, also have the capability for a control or realization of additional control procedures that proceed beyond the actual switching procedure. Such additional functions are generally referred to as performance features, and a great number of different performance features is thereby known, particularly for "voice" communication service. Included among such performance features are the storing of voice messages in what are referred to as mailboxes that are allocated to intended addressees.
A computer-controlled telephone private branch exchange having such mailboxes is already known from the product publications of Siemens AG "HICOM 600 System Product Data", Order No. A19100-K 3161-G430-01-7600 (page 19) and from "ISDN in the Office", Special Issue of Telcom Report and Siemens Magazin COM, pages 56 through 64 and 73-80, ISBM 3-8009-3849-9.
German Published Application DE 37 32 832 A1 already discloses a method and an arrangement for storing telephone messages. Provided among other things in the known method is that messages deposited in the memory of a message addressee are fed back into the memory of the message sender when the message addressee does not fetch the message before a specific point in time.